I've just had to throw out a couple of dozen CDRs which won't play on anything I've got in the house. And they include one or two which were burned within the past couple of years. These latter were admittedly very cheap discs. Against that, I have discs which were burned over ten years ago which still perform perfectly. But that was in the days before cheap CDRs.

My conclusion therefore is that anyone contemplating issuing stuff on CDR should go for the very best quality. And if you've got anything at all on CDR, get it backed up to a computer. God knows, external hard drives are cheap enough nowadays.